In a physical battle, Neptune led 29-24 at the interval but in the second half were on the wrong end of some dubious decisions that saw American Darren Townes fouled out in the third quarter as Killester edged into a four-point lead.
Coming down the stretch Neptune tired as Killester produced crucial baskets, much to the relief of coach Jonathon Grennell.
He said: “We knew Neptune would be tough opponents and credit to them, they pushed us all the way.
“It has been a battle royal all season as we were chasing Demons for many months and now that we have a title apiece I think that the Champions Trophy will be an added bonus to both clubs.”
Neptune coach Mark Scannell was infuriated with the standard of officiating.
“I would like to show these officials the tape and although Killester are worthy champions some of the calls that went against us today certainly didn’t help our cause,” Scannell said.
Demons completed their campaign with a comfortable 84-68 win over Moycullen at Oranmore.
The Cork side had a 44-23 interval lead and with player-coach Colin O’Reilly deciding to sit out the game they still had too much firepower for the westerners, with Lehmon Colbert finishing with 23 points.
DCU Saints guaranteed themselves fourth place when shocking Bord Gais Neptune at the Neptune stadium on Saturday. The Cork side led 37-35 at the break. In the second half Saints out-muscled Neptune on the boards and were allowed score far too many easy baskets, before deservedly running out 71-59 winners.
Templeogue’s disappointing season ended on a losing note at Inchicore against UCD Marian.
The students led 51-44 at the break but with Conor Meany and Kevin Foley producing terrific second-half displays, they chalked up a comfortable 17-point win.
UL Eagles’ top four dream ended when they lost to Killester 80-60 at Clontarf.
The semi-finalists in the Women’s Premier League are now known as Team Montenotte overcame Singleton’s Supervalu Brunell 77-70 in a thrilling quarter-final and Killester beat WIT Wildcats 64-61. That result sets up a mouth-watering semi-final for Killester against defending champions UL Huskies.